Generally, the term “antimicrobial” refers to sterilization, bacteriostasis, anti-mildew, anticorrosion and the like. Antimicrobial agents or preservatives are the materials that can inhibit the growth of microorganism. In daily life, cosmetics are contaminated by microorganism and easily lead to deterioration. Under normal circumstances, this can be reflected on the external appearance. For example, moulds and yeasts usually cause the mildew spots on edges of the packages; turbidity, precipitation, color change, pH change, foaming and change of taste may appear in products contaminated by microorganism; if the products are emulsified bodies, demulsification, pieces and so on may appear. Adding preservatives to cosmetics is to protect the products from the contamination of microorganism. If the amount of preservative added is not enough, there may be microbial adaptation to the surrounding growth environment, resulting in drug resistance, resulting in anti-corrosion failure.
At present, the common preservatives used in cosmetics include hydantoin (DMDMH), Kathon series, bronopol, butyl-carbamic acid 3-iodo-2-propynyl ester (IPBC), Nipagin esters, Triclosan, etc. However, these preservatives have their limitations: for example, DMDMH releases methanol during use and causes potential safety risk; Kathon series contain chlorine and may cause irritation to some skin types; use of bronopol easily generates nitrite amine which is a carcinogen; IPBC may cause the user to overdose iodine; Nipagin esters are accumulated in the adipose tissue easily. In addition, p-hydroxybenzoic acid preservatives have been shown to demonstrate a certain ability to mimic female estrogen in a particular test system, adversely affecting human safety and physiological systems. Triclosan has been shown to have a negative impact on the environment. Therefore, a low toxicity, high efficiency, pollution-free, natural preservative is needed urgently in the market.
In recent years, under the hot-wave of return to nature and enjoying green and health, adding pure natural preservatives to cosmetics becomes a hot spot of promotion and development at home and abroad. Extracting natural antimicrobial agents, which are strong and wide efficiency, safe and non-toxic, from raw materials becomes an important development direction in the future.